Pumps of this type are known.
Vacuum pumps of the abovementioned type can be flange-connected, for example, to the cylinder head of an internal combustion engine. They are then driven by the camshaft of the internal combustion engine. The connection between the camshaft and the rotor of the vacuum pump is produced by way of a coupling, in particular a plug-in coupling. Pumps of this type have oil feed apparatuses, in which the lubricating oil supply of the internal combustion engine is brought into connection with the internal lubricating oil supply of the vacuum pumps by way of oil feed connections in the rotor. It is known to arrange the oil feed connections in such a way that the surfaces which make contact with one another, for example the interfaces between the rotor and the plug-in coupling, are likewise connected to the lubricating oil supply. It is customary to lubricate the interface between the plug-in coupling and the camshaft by way of the oil mist which prevails in the interior space of the cylinder head of the internal combustion engine. However, installation situations are also known, in which no oil mist or insufficient oil mist is available, in order to supply the plug-in coupling with a sufficient quantity of lubricating oil. Plug-in couplings are also known which are partially enclosed by a circumferential wall which is, for example, cylindrical and therefore prevent the oil mist from penetrating from the outside. Plug-in couplings of the abovementioned type are intended to compensate for any existing installation tolerances and can therefore have considerable force and movement changes. An insufficient supply with lubricating oil can therefore lead to considerable wear and to the failure of the vacuum pump.